How much should I charge for graphic design freelancing?

How much should I charge for turning over the original artwork for a print design?

• Please note that I am not asking how much to charge for the entire design, only the additional fee for ownership of the original artwork. Also, my question pertains to design intended for print. Which is more valuable than web images because multiple copies are produced and distributed. I know that the amount of time I put into something will increase the value of my work. For example if I charge $20/hr for my designs that works out to 10 hours = $200 and 20 hours = $400 Does the price for the artwork go up as well? Ideally, I'd like to be able to break down the additional fee by an hourly rate. I'm thinking that an additional $10 -$15 an hour would be ok for me to give up the ownership rights to my work. So for a 10 hour project that would work out to $100 -$150. But I know nothing about Graphic Design Pricing and Ethics. I only know that I feel my work is invaluable so it is hard for me to put a price on it. Any input is appreciated.

• Answer:

  Okay so I just asked my best friend who is a graphic designer, and she agrees that it's really hard to put a price on your own work, so the best way to do it is to charge the amount of time you worked, and that you should charge an additional $10/per hour for the price of the originial artwork.... For example 10 hr = $100 plus $10 hr since your giving up ownership rights = $100, so then charge $200 total...